The energy regulator has confirmed plans for a massive upgrade to the UK's energy grids, adding £108 to customer bills by 2031. Ofgem said on Thursday that the £28bn investment over the next five years would bolster resilience in the transition to a renewable energy future and that much of the bill would be offset by increased efficiency. It pointed to estimated savings for households of around £80 because of the planned investment in gas and power infrastructure, leaving a net additional